Abstract:

A vacuum cleaner with a cyclone module assembly comprises a cyclone
separation chamber for separating dust and debris from air and a
collection chamber for collecting dust and debris that is separated from
the air in the cyclone separation chamber. The cyclone module assembly
further includes at least one feature for directing contaminants
downwardly, such as a circumferential fin that extends from the inside
wall of the collection chamber or a helical step dividing the separation
chamber from the collection chamber.

Claims:

1. A vacuum cleaner comprising:a cyclone separator having at least one
separator chamber for separating contaminants from a dirt-containing
airstream, and further comprising an inlet and an outlet in fluid
communication with the separator chamber;a collection chamber associated
with the cyclone separator for receiving contaminants separated in the
separator chamber and having a sidewall and a bottom wall;a suction
nozzle fluidly connected with the inlet; anda suction source fluidly
connected to the suction nozzle and to the separator chamber for
establishing and maintaining a dirt-containing airstream from the suction
nozzle to the inlet;wherein the collection chamber further comprises at
least one circumferential fin extending inwardly from the sidewall.

2. The vacuum cleaner according to claim 1 wherein the at least one fin
has a helical trajectory to direct contaminants toward the bottom wall.

3. The vacuum cleaner according to claim 1 wherein the at least one fin
extends only partially around the circumference of the collection chamber
and comprises a leading end and a trailing end that is vertically spaced
below the leading end.

4. The vacuum cleaner according to claim 3 wherein the trailing end is
vertical spaced below the leading end a distance in the range of 0.125 to
2.0 inches.

5. The vacuum cleaner according to claim 4 wherein the at least one fin
has a length between 1.0 to 6.0 inches.

6. The vacuum cleaner according to claim 5 wherein the at least one fin
has a width between 0.125 to 1.0 inches.

8. The vacuum cleaner according to claim 7 wherein the fins are laterally
spaced from each other around the circumference of the collection
chamber.

9. The vacuum cleaner according to claim 8 wherein the fins are vertically
staggered relative to each other.

10. The vacuum cleaner according to claim 1 wherein the at least one fin
extends radially in a perpendicular or horizontal or slightly upward
direction from the sidewall toward the center of the collection chamber
so that dust and debris does not accumulate under the at least one fin
when the collection chamber is inverted for emptying.

11. The vacuum cleaner according to claim 1, and further comprising a
separator plate separating the separator chamber from the collection
chamber, the separator plate defining a gap for passage of dirt separated
from the dirt-containing airstream in the separator chamber whereby the
passage of dirt through the gap is accompanied by airflow patterns having
horizontal and vertical components between the gap at one side of the
collection chamber and the bottom wall at an opposite side of the
collection, which airflow tends to entrain dirt particles therein.

12. The vacuum cleaner according to claim 1 wherein the at least one fin
extends only partially around the circumference of the collection chamber
and lies along a common horizontal plane.

14. The vacuum cleaner according to claim 13 wherein the fins are
laterally spaced from each other.

15. The vacuum cleaner according to claim 14 wherein the fins are
vertically staggered relative to each other.

16. A vacuum cleaner comprising:a housing having a sidewall and a bottom
wall and defining a cyclonic separator chamber for separating
contaminants from a dirt-containing airstream, the housing further
comprising an inlet and an outlet in fluid communication with the
separator chamber, and a collection chamber for receiving contaminants
separated in the separator chamber;a suction nozzle fluidly connected
with the inlet; anda suction source fluidly connected to the suction
nozzle and to the separator chamber for establishing and maintaining a
dirt-containing airstream from the suction nozzle to the inlet;wherein
the sidewall comprises a helical step dividing the separator chamber from
the collection chamber to direct contaminants toward the bottom wall.

17. The vacuum cleaner according to claim 16 wherein the helical step is
an inward step such that the sidewall in the region of the collection
chamber has a larger circumference than that of the sidewall in the
region of the separator chamber.

18. The vacuum cleaner according to claim 16 wherein the helical step
extends around the circumference of the housing along an advancing
trajectory.

19. The vacuum cleaner according to claim 16 wherein the housing further
defines a second downstream cyclonic separation chamber and a second
collection chamber for receiving contaminants separated in the second
separation chamber.

20. The vacuum cleaner according to claim 16, and further comprising a
separator plate separating the separator chamber from the collection
chamber, the separator plate defining a gap for passage of dirt separated
from the dirt-containing airstream in the separator chamber whereby the
passage of dirt through the gap is accompanied by airflow patterns having
horizontal and vertical components between the gap at one side of the
collection chamber and the bottom wall at an opposite side of the
collection, which airflow tends to entrain dirt particles therein.

Description:

CROSS-REFERENCE TO RELATED APPLICATION

[0001]This application claims the benefit of U.S. Provisional Patent
Application No. 61/058,995, filed Jun. 5, 2008, which is incorporated
herein by reference in its entirety.

BACKGROUND OF THE INVENTION

[0002]1. Field of the Invention

[0003]The invention relates to suction cleaners, and in particular to
suction cleaners having cyclonic dirt separation. In one of its aspects,
the invention relates to an improved collection chamber configured to
prevent debris re-entrainment.

[0004]2. Description of the Related Art

[0005]Upright vacuum cleaners employing cyclone separators are well known.
Some cyclone separators follow textbook examples using frusto-conical
shape separators and others use high-speed rotational motion of the
air/dirt to separate the dirt by centrifugal force. Typically, working
air enters and exits at an upper portion of the cyclone separator as the
bottom portion of the cyclone separator is used to collect debris.
Furthermore, in an effort to reduce weight, the motor/fan assembly that
creates the working air flow is typically placed at the bottom of the
handle, below the cyclone separator.

[0006]U.S. Pat. No. 6,810,557 to Hansen et al. discloses an upright vacuum
cleaner that has a cyclone separator and a dirt cup. A horizontal plate
separates the cyclone separator from the dirt cup. The air flowing
through the cyclone separator passes through an annular cylindrical cage
with baffles and through a cylindrical filter before exiting the cyclone
separator at the upper end thereof. The dirt tank has fins that project
vertically from a sidewall and from the bottom wall to reduce
re-entrainment of dirt particles. This patent is incorporated herein by
reference in its entirety.

[0007]EP 0 728 435 to Black & Decker discloses a cyclone dust extractor
that has a cyclone separator and a dust collector that is below and
separable from the cyclone separator. A cylindrical collar extends
inwardly and downwardly from a lower portion of the inner surface of the
side wall of the dust collector and against which is said large dust and
debris particles collide, thereby assisting in removing the dust and
debris from the air flow and depositing it in the dust collector. These
dust and debris particle will accumulate in the inverted pocket formed by
the collar when the dust collector is inverted to empty the dust and
debris from the dust collector. A similar construction is disclosed in
the Oh U.S. Pat. No. 6,502,278.

SUMMARY OF THE INVENTION

[0008]According to the invention, a vacuum cleaner comprises a cyclone
separator having at least one separator chamber for separating
contaminants from a dirt-containing airstream, and further comprising an
inlet and an outlet in fluid communication with the separator chamber, a
collection chamber associated with the cyclone separator for receiving
contaminants separated in the separator chamber and having a sidewall and
a bottom wall, a suction nozzle fluidly connected with the inlet, and a
suction source fluidly connected to the suction nozzle and to the
separator chamber for establishing and maintaining a dirt-containing
airstream from the suction nozzle to the inlet. The collection chamber
further comprises at least one circumferential fin extending inwardly
from the sidewall to direct contaminants toward the bottom wall.

[0009]In one embodiment the at least one at least partially
circumferential fin extends along a helical trajectory to direct
contaminants toward the bottom wall. In another of embodiment, the at
least one fin comprises that extends only partially around the
circumference of the sidewall of the collection chamber and thus has a
leading end and a trailing end that lies along a common horizontal plane
with the leading end.

[0010]Further according to the invention, a vacuum cleaner comprises a
housing having a sidewall and a bottom wall and defining a cyclonic
separator chamber for separating contaminants from a dirt-containing
airstream, the housing further comprising an inlet and an outlet in fluid
communication with the separator chamber, and a collection chamber for
receiving contaminants separated in the separator chamber, a suction
nozzle fluidly connected with the inlet, and a suction source fluidly
connected to the suction nozzle and to the separator chamber for
establishing and maintaining a dirt-containing airstream from the suction
nozzle to the inlet. The sidewall comprises a helical step dividing the
separator chamber from the collection chamber to direct contaminants
toward the bottom wall.

BRIEF DESCRIPTION OF THE DRAWINGS

[0011]In the drawings:

[0012]FIG. 1 is a perspective view of an upright vacuum cleaner having a
cyclone module assembly with an improved dirt cup according to a first
embodiment of the invention.

[0013]FIG. 2 is an exploded right front quarter perspective view of the
cyclone module assembly of FIG. 1.

[0014]FIG. 3 is a cross-sectional view of the cyclone module assembly
taken through line 3-3 of FIG. 2

[0015]FIG. 4A is a partial cut-away perspective view of the dirt cup shown
in FIG. 1.

[0016]FIG. 4B is a top view of the dirt cup assembly shown in FIG. 4A.

[0017]FIG. 4c is a top view of a dirt cup assembly according to a second
embodiment of the invention.

[0018]FIG. 4D is a top view of a dirt cup assembly according to a third
embodiment of the invention.

[0019]FIG. 4E is a cross-sectional view of a cyclone module assembly
according to a fourth embodiment of the invention.

[0020]FIG. 5 is a partial exploded view of a filter cartridge and a filter
housing of the upright vacuum cleaner shown in FIG. 1

[0021]FIG. 6 is a cross-sectional view of the filter housing and a motor
housing of the upright vacuum cleaner taken through line 6-6 of FIG. 5.

[0022]FIG. 7 is an exploded perspective view of a cyclone module assembly
according to a fifth embodiment of the invention.

[0023]FIG. 8 is a cross-sectional view of the cyclone module assembly
taken through line 8-8 of FIG. 7.

DESCRIPTION OF THE PREFERRED EMBODIMENT

[0024]Referring to the drawings, and in particular to FIG. 1, an upright
vacuum cleaner 10 comprises an upright handle assembly 12 pivotally
mounted to a foot assembly 14. The handle assembly 12 further comprises a
primary support section 16 with a grip 18 on one end to facilitate
movement by a user. A motor cavity 20 is formed at an opposite end of the
handle assembly 12 to contain a conventional suction source such as a
vacuum fan/motor assembly 22 (FIG. 6) oriented transversely therein. A
filter housing 24 is formed above the motor cavity 20 and is in fluid
communication with the vacuum fan/motor assembly 22. The handle assembly
12 pivots relative to the foot assembly 14 through a pivot axis that is
coaxial with a motor shaft (not shown) associated with the vacuum
fan/motor assembly 22. A recess 40 on the primary support section 16 of
the handle assembly 12 receives a cyclone module assembly 42 according to
a first embodiment of the invention.

[0025]The foot assembly 14 comprises a lower housing 26 that mates with an
upper housing 28 to form a brush chamber 30 therebetween. While not
shown, a rotating brush roll assembly can be positioned within the brush
chamber 30 and operably connected to the motor shaft of the vacuum
fan/motor assembly 22 (FIG. 6) via a stretch belt as is common in the
vacuum cleaner art. Rear wheels 34 are secured to a rearward portion of
the foot assembly 14 and a pair of support wheels (not shown) are secured
to the foot assembly 14 between the brush chamber 30 and rear wheels 34
for moving the foot assembly 14 over a surface to be cleaned. A suction
nozzle 38 is formed at a lower surface of the brush chamber 30 on the
foot assembly 14 and is in fluid communication with the vacuum fan/motor
assembly 22.

[0026]Referring to FIGS. 2 through 4B, the cyclone module assembly 42 of
the first embodiment further comprises a cyclone separator 50 for
separating contaminants from a dirt-containing airsteam and a dirt cup
assembly 66 for receiving contaminants separated by the cyclone separator
50. The cyclone separator 50 includes a first stage cyclone housing 56
defining, in part, a first stage separator chamber 48, and an inner
second stage cyclone housing 52 defining, in part, a second stage
separator chamber 46. The first stage cyclone housing 56 comprises a
generally cylindrical outer wall 62 having an upper wall 61 forming a
closed top and an open bottom, a cyclone inlet 57 formed in the outer
wall 62 and a cyclone outlet 59 formed on the upper wall 61. A first
stage debris outlet 58 is formed by a gap between a separator plate 60
and the outer wall 62. The separator plate 60 separates the first stage
separator chamber 48 from the dirt cup assembly 66.

[0027]As shown in FIG. 3, the frusto-conical shaped second stage cyclone
housing 52 depends from the upper wall 61 of the first stage cyclone
housing 56 and includes an upper cylindrical portion 65 and a lower
frusto-conical portion 67 which mounts the separator plate 60. A pair of
opposed inlets 63 are formed in the cylindrical portion 65 and a second
debris outlet 64 is formed in the bottom of the frusto-conical portion
67.

[0028]A grill assembly 54 is positioned around the cylindrical portion 65
and separates the first stage separator chamber 48 from the second stage
separator chamber 46. The grill assembly 54 includes an outer perforated
wall 176 and an inner wall forming a vortex finder 174. The vortex finder
174 defines a second stage outlet aperture 172 that is in fluid
communication with the cyclone outlet 59.

[0029]The dirt cup assembly 66 comprises a dirt cup housing 68 having an
outer housing wall 78 and an inner housing wall 79 spaced from the outer
housing wall 78 in concentric relation. A first stage collection chamber
70 is formed between the housing walls 78, 79 and a second stage
collection chamber 72 is formed within the inner housing wall 79 and is
sealed off from the first stage collection chamber 70. The dirt cup
assembly 66 sealingly mates with the cyclone separator 50 via a lip 74
formed on a lower surface of the outer wall 62. A first gasket 71 is
positioned between the lip 74 and the upper edge of the outer housing
wall 78. The inner housing wall 79 sealingly mates with a lower surface
of the second stage cyclone housing 52 such that the second debris outlet
64 is in fluid communication with the second stage collection chamber 72
and isolated from the first stage debris outlet 58. A second gasket 73 is
positioned between the separator plate 60 and the upper edge of the inner
housing wall 79.

[0030]The dirt cup assembly 66 further comprises at least one
circumferential fin 76 that extends inwardly from an interior surface of
the outer housing wall 78. The fin 76 functions to direct or urge debris
to the bottom of the collection chamber 70 and keep the separated debris
contained in the first stage collection chamber 70. Each fin 76 comprises
a leading end 80 and a trailing end 82 and has an outer edge 83 that is
attached to the outer housing wall 78 and an inner arcuate edge 84 that
is free. In terms of the working air flow, the leading end 80 of each fin
76 is upstream of the trailing end 82. Optionally, the arcuate edge 84
conforms to the shape of the outer housing wall 78 and can be parallel to
the outer housing wall 78.

[0031]In the illustrated embodiment, multiple intermittently spaced fins
76 are employed. Four spaced fins are shown in FIGS. 2 and 4B. Each fin
76 extends in a perpendicular radial direction from the housing outer
wall 78 but is preferably oriented in a circumferential direction at an
oblique angle with respect to the horizontal, with the leading end 80
vertically spaced above the trailing end 82. Furthermore, adjacent fins
76 can be arranged in a helical fashion, i.e. along a helical trajectory
and furthermore can be vertically staggered such that the leading end 80
of a first fin 76 is vertically spaced from the trailing end 82 of a
second, adjacent fin 76. However, each fin 76 extends horizontally
inwardly from the outer wall 78 toward the center of the dirt cup housing
68.

[0032]The fins 76 can have a length L of approximately 1.0 to 6.0 inches
(25.4 to 152.4 mm), a width W of approximately 0.125 to 1.0 inches (about
3 to 25 mm) wide, and a thickness T of approximately 0.040 to 0.125
inches (about 1 to 3 mm). More specifically, the fins 76 can have a
length L of approximately 3.0 inches (about 76 mm), a width W of
approximately 3/8 inches (about 9-10 mm) wide, and a thickness T of
approximately 1/16 inches (about 1-2 mm). It has been discovered that a
combination of the given specific dimensions for the length L, width W,
and thickness T, and spacing the fins 67 intermittently in a helical
fashion such that the leading end 80 is above the trailing end 82
achieves the best separation efficiency, i.e. the most debris separation
coupled with the least re-entrainment of debris. The lateral spacing S
between fins 76 can measure from about 0.25 inches (about 6-7 mm) to
about 4.0 inches (about 100 mm); however, a preferred distance is about
1.25 inches (about 32 mm). The lateral spacing S between the fins 76
facilitates debris removal as will be described in more detail.
Optionally, the difference in height H1 between the leading end 80
and the trailing end 82 of one of the fins 76 can range from 0.125 to 2.0
inches (about 3 to 51 mm) or be approximately 0.5 inches (about 12.5-13
mm). Furthermore, adjacent fins 76 can optionally be staggered vertically
relative to each other such that the difference in height H2 between
the leading end 80 of a first fin 76 and the trailing end 82 of a second,
adjacent fin 76 is in the range of 0.125 to 2.0 inches (about 3 to 51
mm), preferably approximately 0.5 inches (12.5-13.0 mm).

[0033]Referring to FIG. 4c, a dirt cup assembly 66' according to a second
embodiment of the invention is shown. The dirt cup assembly 66' is
substantially identical to the dirt cup assembly 66 shown in FIG. 4B,
except for the fin arrangement, which comprises three intermittently
spaced fins 76'.

[0034]Referring to FIG. 4D, a dirt cup assembly 66'' according to a third
embodiment of the invention is shown. The dirt cup assembly 66'' is
substantially identical to the dirt cup assembly 66 shown in FIG. 4B,
except for the fin arrangement, which comprises a single fin 76''. The
fin 76'' can extend in a helical or spiral fashion around the outer
housing wall 78''. Optionally, the fin 76'' can extend less than
360° around the circumference of the wall 78'' so that the leading
end 80'' does not overlap the trailing end 82'' or the fin 76'' can
extend more than 360° around the circumference of the wall 78'' so
that the leading end 80'' overlaps the trailing end 82''. Alternately, as
illustrated herein, the fin 76'' can extend approximately 360°
around the circumference of the wall 78'' such that the leading end 80''
and the trailing end 82'' lie along a common plane.

[0035]Referring to FIG. 4E, a cyclone module assembly 42 according to a
fourth embodiment of the invention is shown. The cyclone module assembly
42 is substantially identical to the cyclone module assembly 42 shown in
FIG. 3, except for the fin arrangement, and like elements will be
referred to with like reference numerals. As illustrated, the third
embodiment comprises at least one partial circumferential fin 184 that
extends horizontally inwardly from an interior surface of the outer
housing wall 78 and functions to direct or urge debris to the bottom of
the collection chamber 70 and keep the separated debris contained in the
first stage collection chamber 70. Each fin 184 is discontinuous in that
it extends only partially around the circumference of the collection
chamber 70 and comprises a leading end 186 and a trailing end 188. In
terms of the working air flow, the leading end 186 of each fin 184 is
upstream of the trailing end 188.

[0036]In the illustrated embodiment, multiple intermittently spaced fins
184 are employed. Two fins 184 are visible in FIG. 4E, but is envisioned
that 3 or more fins can be employed with this embodiment. Each fin 184 is
preferably oriented horizontally, with the leading end 186 and the
trailing end 188 lying along a common horizontal plane. In addition, each
fin 184 extends radially in a perpendicular direction (or horizontally)
from the outer wall 78 toward the center of the dirt cup housing 68 so
that dust and debris does not accumulate under the spaced fins when the
collection chamber 70 is inverted for emptying. Although not shown, each
fin 184 can extend inwardly and upwardly at an acute angle to the outer
wall 78, if desired. The intermittently spaced fins 184 also provide
slightly improved efficiency of separation and ease of dumping the dust
and debris than annular fins as, for example, illustrated in the prior
art references cited above. Furthermore, adjacent fins 184 can be
vertically staggered so that the leading end 186 of a first fin 184 is
vertically spaced from the trailing end 188 of a second, adjacent fin
184. The fins 184 can have the same dimensions given above for the first
embodiment, except that the fins 184 will not have a height H1 since
the leading end 186 and trailing end 188 lie along a common horizontal
plane.

[0037]As shown in FIGS. 5 and 6, the vacuum fan/motor assembly 22
comprises a motor assembly 85 and a fan assembly 86. The vacuum fan/motor
assembly 22 further includes a fan chamber 89 in fluid communication with
a working air inlet 91 and a working air outlet 93. The motor assembly 85
includes a motor cooling air inlet 95 and a motor cooling air outlet 97.

[0038]The filter housing 24 comprises a filter compartment 88 having a
dividing wall 90 that separates the filter compartment 88 into a working
air inlet region 92 and a working air outlet region 96 that is separate
from the working air inlet region 92. The working air inlet region 92
fluidly communicates a working air conduit 94, which is in fluid
communication with the cyclone outlet 59 (FIG. 2) with the working air
inlet 91 of the fan chamber 89 after passing the working air through a
pre-motor filter. The working air outlet region 96 fluidly communicates
the motor cooling outlet 97 with the external atmosphere after passing
the working air through an exhaust filter.

[0039]A substantially disk shaped filter cartridge or assembly 98 is
sealed within the filter compartment 88. In one embodiment, the filter
assembly 98 comprises a substantially rigid filter frame 100 comprising a
vertical annular wall 102 formed in a circular shape, with a dividing
wall 104, which can be substantially aligned with the dividing wall 90,
formed across the center thereof to divide the filter frame 100 into two
distinct regions; a pre-motor filter region 106 and an exhaust filter
region 108. The pre-motor filter region 106 and exhaust filter region 108
are bounded by a section of the annular wall 102 and the dividing wall
104 and have a semi-circular shape. The pre-motor filter region 106
preferably receives a commonly known filter media 110 such as open cell
foam or other known suitable material that is formed to fit the
semi-circular shape of the region 106. The exhaust filter region 108
preferably receives known filter media 112 such as pleated paper, HEPA
media, pleated HEPA media, non-woven filter media, or the like, and is
also formed in a semi-circular shape. Optionally the filter media 110 can
be removable from the filter frame 100 and that filter media 112 can be
sealed to the filter frame 100 with a suitable sealant such as silicone
or the like. A filter cover 114 is sealingly fixed to the top surface of
the filter frame 100 and seals each distinct filter region 106, 108 from
the other. The filter cover 114 comprises a plurality of exhaust
apertures 116 above the exhaust filter region 108 in fluid communication
with the external atmosphere. The filter cover 114 is preferably user
removable via a commonly known twist lock latch 118 or other mechanism
such as a hinged cover with retaining latch to allow easy user-access to
the filter media 110, 112 for replacing or cleaning thereof The filter
cover 114 can also include a keying feature (not shown) to permit only a
unique orientation of the cover 114 on the filter frame 100.

[0040]Referring to FIGS. 3 and 6, in which the flow path of air is
indicated by arrows, the operation of the separators will be described.
The vacuum fan/motor assembly 22 is positioned downstream of the cyclone
outlet 59 such that when energized, establishes and maintains a
dirt-containing airstream from the suction nozzle 38 to the cyclone
separator 50. The vacuum fan/motor assembly 22 draws air from the suction
nozzle 38 (FIG. 1) to the cyclone inlet 57 and into the cyclone separator
50 where the dirty air to swirls around the first stage separator chamber
48. Larger debris falls into the first stage collection chamber 70 of the
dirt cup assembly 66 via the gap 58. The intermittently spaced fins 76
force the debris to the bottom of the collection chamber 70 and keep the
separated debris contained in the first stage collection chamber 70. The
working air then passes through the outer perforated wall 176 of the
grill assembly 54 to filter out any remaining large debris and enters the
second stage separator chamber 46 via the second stage inlet inlets 63.
The second stage inlets 63 direct the air tangentially and downwardly
along an inside surface of the second stage cyclone housing 52. The
airflow turns near the second stage debris outlet 64 and proceeds
directly upward to the second stage outlet aperture 172 and through the
cyclone outlet 59. The dirt removed in the second stage separator chamber
46 falls into the second stage collection chamber 72.

[0041]From the cyclone outlet 59, the working air travels through the
working air conduit 94 and is delivered to the pre-motor filter region
106 of the filter assembly 98 where any remaining small dust particles
are trapped by the filter media 110 prior to the air being drawn into the
vacuum fan/motor assembly 22. Working air is then drawn into the working
air inlet 91, through the fan chamber 89 and is exhausted through the
working air outlet 93. The working air then enters the motor cooling
inlet 95, is drawn over the motor assembly 85, thereby reducing its
working temperature, and is then exhausted through the motor cooling
outlet 97. From the motor cooling outlet 97, the working air travels
through the outlet region 96 and is forced through the exhaust filter
region 108 of the filter assembly 98, where any remaining debris or brush
motor dust is trapped in the exhaust filter media 112, and, finally,
through the exhaust apertures 116 in the filter cover 114 and into the
external atmosphere.

[0042]To dispose of collected dirt and dust, the dirt cup assembly 66 is
detached from the cyclone separator 50 to provide a clear, unobstructed
path for the debris captured in both the first stage collection chamber
70 and the second stage collection chamber 72 to be removed. Dust and
dirt disposal is accomplished by inverting the dirt cup assembly 66.

[0043]Referring to FIGS. 7 and 8, a cyclone module assembly 120 according
to a fifth embodiment of the invention is shown and comprises an outer
housing 122, a grill assembly 124, an inner housing 162, and a bottom
debris release door 128. The outer housing 122 has an open bottom that
can be selectively closed by the door 128, a closed top formed by an
upper wall 143 and a side wall comprising a lower dirt cup wall 145
joined with an upper first stage separation chamber wall 146 via an
inward step 148 such that the dirt cup wall 145 has a larger
circumference than the first stage separation chamber wall 146. The
inward step extends around the circumference of the housing 122 along an
advancing helical trajectory. The outer housing 120 further comprises a
working air inlet 130 formed in the first stage separation chamber wall
146 an outlet 132 formed in the upper wall 143. The outlet 132 can be in
fluid communication with the conduit 94 (FIGS. 5 and 6).

[0044]The cyclone module assembly 120 further comprises a first stage
separation chamber 134, a first stage collection chamber 136, a second
stage separation chamber 138, and a second stage collection chamber 140.
The first stage cyclone separation chamber 134 is formed between the
grill assembly 124 and the first stage separation chamber wall 146. A
first stage debris outlet 142 is formed by a gap between a separator
plate 144 mounted on the inner housing 162 and the first stage separation
chamber wall 146. The first stage collection chamber 136 is formed
between the inner housing 162 and the dirt cup wall 145. The junction
between the first stage separation chamber 134 and its corresponding
collection chamber 136 is defined by the inward step 148. In other words,
the inward step 148 divides the first stage separation chamber 134 from
the collection chamber 136.

[0045]The inner housing 162 is positioned between the upper wall 143 and
the release door 128 and comprises a frusto-conical separator 126 and a
second stage debris collector 155 beneath the frusto-conical separator
126. The frusto-conical separator 126 defines the second stage separation
chamber 138, which is positioned concentrically and in series with the
first stage separator chamber 134, and includes an upper cylindrical
portion 178, a lower cylindrical portion 180 which mounts the separator
plate 144, and a cone-shaped portion 182 formed between the cylindrical
portions 178, 180. A pair of opposed inlets 152 are formed in the upper
cylindrical portion 178 and a second debris outlet 154 is formed in the
lower cylindrical portion 180. The debris outlet 154 is fluidly connected
to the second stage debris collector 155.

[0046]The second stage debris collector 155 comprises a second cone-shaped
portion 160 and a debris collection cylinder 156 beneath the cone-shaped
portion 160. The cone-shaped portion 160 defines a frusto-conical chamber
157 that terminates into the cylindrical second stage debris collection
chamber 140, which is defined by the debris collection cylinder 156. The
frusto-conical chamber 157 flares outwardly from the second stage debris
outlet 154 to create a horizontal step 159 that extends outwardly from
the perimeter of the lower cylindrical portion 180. The cone-shaped
portion 160 extends downwardly and inwardly from the outer edge of the
horizontal step 159 and fluidly connects to the debris collection
cylinder 156 on a bottom side thereby joining the respective internal
chambers 157 and 140. The bottom surface of the second stage debris
collection chamber 140 sealingly mates to the debris release door 128 in
selective fashion such that the second stage debris outlet 154 is
isolated from the first stage debris outlet 142. The second stage
collection chamber 140 can be formed by a separate second stage cyclone
housing 162, or, alternatively, it can be formed as part of the outer
housing 122.

[0047]In a preferred embodiment, the debris release door 128 is movable
between a first and second position. In the first, closed position, shown
in FIG. 8, the debris release door 128 is located adjacent to the bottom
of the dirt cup wall 145 of the outer housing 122 and forms the bottom
wall of the first and second stage collection chambers 136, 140. The door
128 is configured to selectively pivot away from the dirt cup wall 145,
thus creating an opening at the bottom side of the first and second stage
debris collection chambers 136, 140 to allow easy, simultaneous emptying
of the outer and inner housings 122, 162.

[0048]The operation of the alternate cyclone module assembly 120 will now
be described with reference to FIG. 8, in which the flow path of air is
indicated by arrows. In operation, the vacuum fan/motor assembly 22 is
positioned downstream of a cyclone outlet 132. When energized, the vacuum
fan/motor assembly 22 draws air from the suction nozzle 38 to the cyclone
inlet 130 and into the outer housing 122 where the dirty air to swirls
around the first stage separation chamber wall 146 of the first stage
cyclone separation chamber 134. Larger debris falls into the first stage
collection chamber 136. The inward step 148 formed on the cyclone housing
122 functions to direct or urge the debris to the bottom of the
collection chamber 136 and keep the separated debris contained in the
collection chamber 136. The working air then passes through the grill
assembly 124 to filter out any remaining large debris and enters the
second stage separator 138 via the second stage inlets 152. The second
stage inlets 152 directs the air tangentially and downwardly along an
inside surface of the frusto-conical separator 126. The airflow turns
near the second stage debris outlet 154 and proceeds directly upward and
through the cyclone outlet 132. The dirt removed by the frusto-conical
separator 126 falls into the second stage debris collector 155 beneath.

[0049]The second stage debris collector 155 collects and retains dirt that
is removed from the working air stream in the inner housing 162 and
dropped through the second stage outlet 154. The outward flare of the
second frusto-conical chamber 157 reduces the velocity of the working air
stream in the second stage debris collector 155, to prevent
re-entrainment of dirt in the second stage collection chamber 140. The
horizontal step 159 provides additional debris re-entrainment prevention
by blocking any lingering debris swirling around the inner surface of the
cone-shaped portion 160 from entering the second stage debris outlet 154.
The working air continues to travel through the working air conduit 94
(FIG. 6) and is delivered to the pre-motor filter region 106 of the
filter assembly 98, as described above, before passing through the vacuum
fan/motor assembly 22, the exhaust filter region 108 of the filter
assembly 98 and, finally, into the external atmosphere. To dispose of
collected dirt and dust, the debris release door 128 can be selectively
pivoted away from the bottom of the dirt cup housing 122 to allow debris
to fall out of the first and second collection chambers 136, 140
simultaneously.

[0050]While the invention has been specifically described in connection
with certain specific embodiments thereof, it is to be understood that
this is by way of illustration and not of limitation. For example, while
the cyclone module assemblies illustrated herein are shown having two
stages of separation, it is understood that the improvements to the
collection chamber could be applied to a single stage separator, or other
types of cyclone separators. Reasonable variation and modification are
possible with the scope of the foregoing disclosure and drawings without
departing from the spirit of the invention which, is defined in the
appended claims.